Microbiota-accessible carbohydrates suppress Clostridium difficile infection in a murine model.
Hryckowian AJ, Van Treuren W, Smits SA, Davis NM, Gardner JO, Bouley DM, Sonnenburg JL
Nat Microbiol. Apr 2018. doi: 10.1038/s41564-018-0150-6
COMMENT: In this work the authors show that microbiota-accessible carbohydrates (MACs) in the diet critically influence the Clostridium difficile infection. Using a mouse model of antibiotic-induced Clostridium difficile infeccion they demonstrate that MACs-deficient diets perpetuate Clostridium difficile infection.
Clostridium difficile infection is associated with antibiotic treatments and only 22% of individuals with Clostridium difficile infection have no recent history of antibiotic treatments. The authors of this work used an experimental model of Clostridium difficile infection in ex-germ-free Swiss-Webster mice colonized with the microbiota of a healthy human donor. One group of mice was fed with a diet deficient in MACs and another group was fed with a diet rich in MACs. Mice with MACs-deficient diets showed persistent Clostridium difficile infection, whereas mice with MACs+ diet cleared the C. difficile within 10 days of infection. Moreover, a dietary shift to the MACs+ diet in the group with persistent infection also resulted in clearance of the infection.
16S rRNA sequencing allowed seeing different alpha and beta diversity patterns in both groups and to study the kind of bacterial taxa that correlated and anti-correlated with the Clostridium difficile infection. Considering the previously suggested idea that metabolites, rather than microorganisms, are able to determine the Clostridium infection status in humans the authors hypothesized that the diet could create metabolic landscapes either supportive or unsupportive for C. difficile. As a result of their investigations the authors affirm that acetate, propionate and butyrate have concentration-dependent negative effects on C. difficile growth.
Other human trials based on diet intervention for bacterial infection recovery have shown that cooked green bananas (rich in MACs), producing elevated levels of SCFAs in the stool of treated patients, aid host recovery from Shigella infections.
In conclusion the authors affirm:
Taken together, our work is part of a growing body of literature providing evidence that dietary manipulation of the metabolic networks of the intestinal tract is a powerful and underexplored way to influence gastrointestinal pathogens